Steam-turbine.



PATENTED JULY 16, 1907.

7 T. F. SHERIDAN. STEAM TURBINE. APPLICATION IIILED DEO. 26,1905.nnnnwnn 131:0. 17, 1906.

Mags UNITED STATES PATENT OFFICE.

THOMAS F. SHERIDAN, OF CHICAGO, ILLINOIS ASSIGNORTO ALLIS-CHALMERSCOMPANY, OF MILWAUKEE, WISCONSIN, A CORPORATION OF NEW JERSEY.

STE AM-TURB INE Specification of Letters Patent.

Patented July 16, 1 907.

Application filed December 26, 1905. Renewed December1'7, 1906. SerialNo. 348,292.

new and useful Improvements in Steam-Turbines, of

which the following is a specification.

My invention relates to improvements in elastic fluid or steam turbines,having special reference to turbines of the Parsons type, and has forits object to improve the construction of the rotor of the turbine, byproviding a multi-part tubular shaft or rotor with simple and economicalmeans for effectually joining or holding the parts together While inoperative condition. 7

The invention consists in the features, combinations and details ofconstruction hereinafter described and claimed.

In the drawings-Figure 1 is a longitudinal sectional detail of a portionof one end of a steam turbine rotor, as it appears when constructed inaccordance with my improvements. Fig. 2 is a cross sectional view, takenon the line2 of Fig. 1, looking in the direction of the arrow.

In turbines of the Parsons type, it is desirable to construct the rotorin such manner that it will combine extreme rigidity and strength withlightness, as it is well-known that the rotative speeds in this class ofengines is extremely high.

To attain these objects, I construct a rotor comprising a hollow shaftor tubular portion a, of the desired size,

' shape and strength. This main tubular portion has an enlarged centralbore a, and each end of the shaft of the rotor is provided with a,preferably, reduced parallel cylindrical bore 0, though this may be ofany sizein fact, the entire bore of the length of the main portion maybe of uniform diameter and provided with grooves near each end insteadof the large bore. The large bore is for the purpose of making the shaftlighter than it otherwise would be, as well as for preventing the toolfrom running into or forming a shoulder when boring either end. Each endof the rotor shaft is turned down to reduced diameter, so as to providea tapered end portion b and a shoulder portion b. I

For the purpose of strengthening each end of the rotor shaft after ithas been bored and for closing each end of the rotor shaft, a plug (1 isprovided, of a diameter slightly larger than the bore 0. This plug maybe driven into position, or it may be inserted by the ordinary shrinkingoperation, preferably, by shrinking when conditions or circumstancesWill permit. It will be seen, therefore, that the rotor shaft when thusformed and the plugs inserted is to all intents and purposes a solidshaft with reinforced closed ends. By

\ closing the ends of the rotor shaft in the manner described, not onlyare the ends strengthened, but the moisture and deleterious elements areprevented from entering into the bore where any injurious action cannotbe readily discovered or minimized. The ends thus strengthened form alsoa firm and rigid support for the 'drums of the turbine, as will behereinafter described. After the plugs are put into position, the rotorshaft should be re-centered and machined for its finishingoperationsthat is, the tapered end portion each end of the rotor shaft,I, preferably, make stub shafts having cap portions e, bored out orrecessed and tapered, so as to fit the taper b at each end of the rotorshaft. These stub shafts are preferably formed in such a manner thatthey will come in close contact with the shoulder b.

When the parts are in positionor previous to assembling-a-multip1icityof key-ways is provided in both the main and cap parts of the rotorshaft, in which are inserted keys f to prevent independent lateralmovement of the parts. A plurality of headed bolts or cap screws 9 isalso provided and passed through the encircling cap portions of the stubshafts into threaded engagement with the ends of the main rotor shaftportion, as shown particularly in the drawings. The shafts and keystogether prevent lateral and longitudinal motion of the parts-the screwspreventing independent longitudinal movement, while the keys prevent theindependent lateral. movements of the parts. The keys also take off allshearing action of the bolts-all of which will be understood andappreciated by those skilled in the art.

The stub shafts are provided with reduced extensions 6. These extensionsmay be machined to form journal portions, which can be fitted in desiredbear ings in the stator or casing of the mac-hine-not shown.

One of the drum portions h, for the rotor carrying blades 1', is fittedover the rotor shaft so as to engage the end of the main portion of therotor and a part of the encircling cap. The drum portion thus serves tohold the parts in longitudinal .alinement, While the solid constructionof the shaft at this end, as before mentioned, furnishes a secure andrigid support for the drum.

Although I have shown in the drawings the construction of the rotor atone end only, it will be understood that the construction is the same atboth ends.

I claim:"

1. In an elastic fluid turbine, a turbine rotor comprising a hollow mainportion with reduced ends, a plug portion tightly inserted in each ofthe open ends of the tubular portion so as to re-inforce and strengthenthe same, a

stub shaft portion provided with an encircling cap fitting the reducedportions at each end of the main portion, and means to preventindependent movement of the parts.

2. In an elastic fluid turbine, a rotor comprising a main hollow portionhaving closed ends, the ends of the main portion being reduced, a stubshaft having an encircling cap fitting each reduced end of the shaft,and means for securing the parts together to prevent independentmovement thereof.

3. In an elastic fluid turbine, a rotor comprising a main tubularportion provided with enlarged central and reduced end bores and reducedexterior tapered portions on each end of the tubular portion, a plugtightly and rigidly inserted in each of the reduced bores at each end ofthe tubular portion so as to reinforce the same, grooves in the tubularportion and the stub shaft keys inserted therein to prevent independentlateral movement of the parts, and bolts passed through the cap portionof the stub shafts and engaging the ends of the tubular portion toprevent independent longitudinal movement of the parts.

4. In an elastic fluid turbine, a rotor consisting of a hollow portionhaving reduced ends, a plug tightly and rigidly inserted in each of theopen ends of the tubular portion, a stub shaft portion provided with acap encircling the reduced ends of the tubular portion, means to preventindependent movement of the parts, and a bladed drum mounted on thetubular portion over the joints between the tubular portion and the stubshafts.

THOMAS F. SHERIDAN.

Witnesses ANNIE C. COURTENAY, JENNIE A. MACEDWARD.

